The present invention relates to an innovative gate movement drive.
In the prior art gate drives comprise a motor unit which moves the gate and an electrical/electronic circuit which controls the motor unit and supervises the opening and closing phases. In particular the control circuit receives gate opening and closing signals and actuates in a corresponding manner the motor unit usually for a time period which is predetermined to be sufficient to take the gate to the required condition. More rarely there is also provided a stop which is operated by the gate when it reaches the fully closed or open position in such a manner as to stop the motor unit upon actual achievement of the fully closed or open position. However closed or open stopping is achieved the gate always moves at maximum speed to the stop position and then always stops violently against the mechanical stops.
Some drives also have the capability of controlling the gate to move it to a predetermined intermediate position to provide a barrier against the entry of vehicles but permit foot traffic. This capability is usually afforded by providing an opening movement for a time assumed necessary to provide the desired passage. Unfortunately changes in the timing or speed of movement of the gate due to deterioration of the components, wear, changes in environmental conditions etcetera often make this function unreliable.
Lastly, some drives have sensors which measure the opening and closing effort and permit detection of obstacles to gate movement. When such a condition is detected the drive locks or reverses gate movement. But it has been noted that in some cases reversal of motion can be dangerous and especially in the case where the obstacle consists of a person trapped by moving parts of the gate. Even mere stopping suffers however from the shortcoming of often keeping the obstacle trapped between the gate and its stop striker.
Because of the widespread use of conventional drives as described above it is very difficult to develop alternative solutions which would be functionally satisfactory but at the same time compatible with the existing mechanical and electromechanical parts.
The general purpose of the present invention is to obviate the above mentioned shortcomings by making available a gate drive which would permit more accurate and steady gate movement control together with the capability of simplicity of mechanical installation of the parts peculiar to the new drive.